chapter 2

Question 1

a number that designates a particular memory location.

Answer 1

address

Question 2

a main memory allocation scheme that considers all free blocks and selects for allocation the one that will result in the least amount of wasted space.

Answer 2

best-fit memory allocation

Question 3

a register used to store the highest location in memory legally accessible by each program

Answer 3

bounds register

Question 4

the process of collecting fragments of available memory space into con- tiguous blocks by moving programs and data in a computer’s memory or disk. Also called garbage collection.

Answer 4

compaction

Question 5

the process of freeing an allocated resource, whether memory space, a device, a file, or a CPU.

Answer 5

deallocation

Question 6

a memory allocation scheme in which jobs are given as much memory as they request when they are loaded for processing, thus creating their own partitions in main memory.

Answer 6

dynamic partitions

Question 7

a situation in which the dynamic allocation of memory creates unusable fragments of free memory between blocks of busy, or allocated memory.

Answer 7

external fragmentation

Question 8

a nonpreemptive process scheduling policy that handles jobs according to their arrival time; the first job in the READY queue is processed first.

Answer 8

first come first served (FCFS)

Question 9

a main memory allocation scheme that searches from the beginning of the free block list and selects for allocation the first block of memory large enough to fulfill the request.

Answer 9

first-fit memory allocation

Question 10

a memory allocation scheme in which main memory is sectioned off, with portions assigned to each job.

Answer 10

fixed partitions

Question 11

a situation in which a fixed partition is only partially used by the program; the remaining space within the partition is unavailable to any other job and is therefore wasted.

Answer 11

internal fragmentation

Question 12

a unit of memory or storage space equal to 1,024 bytes or 210 bytes.

Answer 12

kilobyte

Question 13

the unit that works directly with the CPU and in which the data and instructions must reside in order to be processed. Also called random access memory (RAM), primary storage, or internal memory.

Answer 13

main memory

Question 14

an empty entry in a list.

Answer 14

null entry

Question 15

a memory allocation scheme in which the system relocates programs in memory to gather together all of the empty blocks and compact them to make one block of memory that’s large enough to accommodate some or all of the jobs waiting for memory.

Answer 15

relocatable dynamic partitions

Question 16

(1) the process of moving a program from one area of memory to another; or (2) the process of adjusting address references in a program, by either software or hardware means, to allow the program to execute correctly when loaded in different sections of memory.

Answer 16

relocation

Question 17

a register that contains the value that must be added to each address referenced in the program so that it will be able to access the correct memory addresses after relocation.

Answer 17

relocation register

Question 18

another term for fixed partitions.

Answer 18

static partitions